Sink drain and vent remode

[JRLND]

See attached photo. I am redoing the rough in for my sink plumbing. I currently have 1 lab and am switching to 2. I need help on how to properly set drains and vents to meet code.

 

[Reach4]

ND is UPC.

You are only adding one lavatory,

Let's see what is going on at the right end of that horizontal pipe, on the other side of the toilet.

 

[Sponsor]

 

[JRLND]

I am putting in 2 lavs now. To the right, the current single lav, 1.5” pipe, goes to a T on the main 3” vertical vent/drain

 

[JRLND]

This is what I came up with. Not sure if it’s code.

 

[wwhitney]

That connectivity works as a horizontal wet vent under the UPC if the pipe from the right lav connection to the stack is 2". The UPC only allows 1 DFU on a 1-1/2" horizontal drain.

https://up.codes/viewer/north_dakota/upc-2018/chapter/7/sanitary-drainage#703.2

Fittings-wise, the left lav needs a LT90 to turn into the wall, and the right lav needs a horizontal combo (2x1-1/2x1-1/2) where the drains join. The vertical vent takeoff needs to be an upright 1-1/2" combo.

Cheers, Wayne

 

[JRLND]

Thanks for the help. It is greatly appreciated. The left needs a long turn, but the right lav just a combo? This is what I currently have. I will have to cut out and put a 2" pipe there. https://www.menards.com/main/plumbi...ee-abs-dwv/i09845c/p-1444449191636-c-8562.htm

 

[wwhitney]

The left needs a long turn, but the right lav just a combo?

A quarter bend and a san-tee (what you linked to) have the same curvature. That curvature is enough for a drain turning from horizontal to vertical. So the san-tee can only be used for drainage with the barrel vertical.

For horizontal to horizontal drainage turns, you need more curvature. That's provided by using two 45s, or equivalently a long turn 90. Likewise by using a wye fitting plus a 45, or equivalently a combo.

The extra curvature is also required when a drain turns from vertical to horizontal. The UPC requires the vent takeoff to be plumbed like a drain in case it ever fills from a blockage. So your vent take off needs to be an upright wye plus 45, or a combo.

Cheers, Wayne

 

[Reach4]

In practice, the bend on the left is often a medium in UPC areas instead of long:

https://terrylove.com/forums/index.php?threads/which-quarter-bend-for-lav-drain.88188/#post-632527
https://terrylove.com/forums/index.php?threads/full-bathroom-addition.86579/#post-621248
https://terrylove.com/forums/index.php?threads/poll-increasing-trap-arm-diameter.89938/ #5.

I don't know about the fitting for the right-hand lavatory.

Long sweeps are always nice if you have the space.

 

[JRLND]

Awesome. I have the final design done now, thanks. Only issue is splicing in to the main-vertical 3” vent/drain. I have wyes for it, but won’t be able to make the connections due to limited movement of pipe and all of the other connections. Can I use a rubber coupling? I bought 2. See attached. I can not find that in the UPC.

 

[JRLND]

I see these are not ASTM D3212 certified, which the UPC calls out. I can't even find a flexible coupling that meets that.

 

[Reach4]

Can I use a rubber coupling? I bought 2. See attached. I can not find that in the UPC.

You can use the one with the stainless steel band (P3000-33). The band can be slid away as you get the rubber into position. Liquid dish detergent is often used as a lube for the rubber.

Often you will need two (to insert a segment), and sometimes you can get by with one.

 

[wwhitney]

You can use a shielded rubber coupling. For 3" plastic to 3" plastic, it would be Fernco 3005-33 or Mission P-300. The requirement is ASTM C1460, and the reference is here:

https://up.codes/viewer/north_dakota/upc-2018/chapter/7/sanitary-drainage#705.10

Note that does say "different materials" but I understand that's routinely ignored and use for connecting the same material. It's also a bit silly, as you could do your new work in PVC and cut it into the existing ABS and it would certainly comply. But then whether your new work is PVC or ABS should have no bearing on the acceptability of the end result.

Cheers, Wayne

Edit PS I think the first sentence of 705.1.1 also allows a shielded coupling without specifying the necessary ASTM compliance. The next sentence in reference to ASTM D3212 is only for push-on joints. Which I understand to be something like a gasketed bell end of a sewer pipe.

https://up.codes/viewer/north_dakota/upc-2018/chapter/7/sanitary-drainage#705.1.1

 

[JRLND]

Thanks for all of the help. I sure hope this is legal. Here’s a pic

 

[wwhitney]

Looks good to me, as long as the lower san-tee in the second picture is at least 6" above the vanity sink rim.

I think technically the 1-1/2" to 2" transition should have occurred between the vent combo and the combo for the right hand sink. The UPC calls for the trap arm to be the same size as the fixture trap (although that's routinely violated for a 1-1/4" sink trap on a 1-1/2" trap arm). And the trap arm extends up to the vent takeoff, which is the vent combo. But I don't think enlarging it earlier like you have is an actual problem.

Cheers, Wayne

 

[JRLND]

Ahhh crap.....luckily it's not a terrible fix to cut out and move that transition, but I think I'll leave it and see if he gives me a hard time.

Counter top (flood rim) to bottom of san-tee pipe is 5"...my new vanity is 35" top of counter, which must have been taller than the old...I can't remember. Splicing in to the vent stack was a pain, so I'm going to go with it. Worse case I'll have to drop the vanity design down to 34".

Big thanks for the responses. You've been a huge help.

 

[JRLND]

6" to center of pipe (san-tee connection)